Outboard engine

ABSTRACT

There are included: a motor contained in a top cover; a vertical shaft that is rotationally driven by the motor, the vertical shaft being contained in an extension casing; and a propeller that is rotationally driven by the vertical shaft, the propeller being provided at a gear casing, wherein a heat exchanging part is provided inside a front portion of the gear casing, and inside the heat exchanging part, there are formed an inflow-side oil channel and an outflow-side oil channel that cooling oil for cooling the motor flows through.

INCORPORATION BY REFERENCE

The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2022-030011 filed on Feb. 28, 2022. The content of the application is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an outboard engine, and specifically, relates to an outboard engine driven by an electric motor.

Description of the Related Art

There has been conventionally disclosed an outboard engine including, for cooling the outboard engine, a heat exchanging part that cools a coolant such as cooling oil through underwater heat exchange (for example, U.S. patent Ser. No. 10/533,484).

SUMMARY OF THE INVENTION

The conventional technology however has a problem that since the heat exchanging part for heat exchange of the coolant is installed in a rear portion of the outboard engine, it is affected by heat generated by the outboard engine and the coolant cannot be efficiently cooled.

The present invention is devised in view of the aforementioned circumstances, and an object thereof is to provide an outboard engine capable of efficiently cooling cooling oil for a motor.

In order to achieve the aforementioned object, there is provided an outboard engine according to an aspect of the present invention, including: a motor contained in a top cover; a vertical shaft that is rotationally driven by the motor, the vertical shaft being contained in an extension casing; and a propeller that is rotationally driven by the vertical shaft, the propeller being provided at a gear casing, wherein a heat exchanging part is provided inside a front portion of the gear casing, and inside the heat exchanging part, an oil channel is formed that cooling oil for cooling the motor flows through.

According to an aspect of the present invention, since the heat exchanging part is formed in a front portion of the gear casing, running water is to touch the heat exchanging part while a vessel is travelling using the outboard engine. Therefore, by forming the oil channel in the heat exchanging part, the cooling oil flowing in the oil channel can be efficiently cooled.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational sectional view showing an embodiment of an outboard engine according to the present invention;

FIG. 2 is a transverse sectional view of a top cover portion of the outboard engine;

FIG. 3 is an elevational sectional view of a motor portion;

FIG. 4 is an elevational sectional view showing an embodiment of a heat exchanging chamber;

FIG. 5 is a transverse sectional view of an upper part of the heat exchanging chamber, showing an embodiment of the heat exchanging chamber;

FIG. 6 is an elevational sectional view showing a modification of the heat exchanging part;

FIG. 7 is a schematic configuration view showing a modification of the heat exchanging part;

FIG. 8 is a transverse sectional view showing a modification of the heat exchanging part; and

FIG. 9 is a transverse sectional view showing a modification of the heat exchanging part.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment

FIG. 1 is an elevational sectional view showing an embodiment of an outboard engine. FIG. 2 is a transverse sectional view of a top cover portion of the outboard engine. FIG. 3 is an elevational sectional view of a motor portion. FIG. 4 is an elevational sectional view showing an embodiment of a heat exchanging chamber. FIG. 5 is a transverse sectional view of an upper part of the heat exchanging chamber, showing an embodiment of the heat exchanging chamber.

An outboard engine 10 is attached to the stern of a hull.

As shown in FIG. 1 , the outboard engine 10 includes a top cover 11, an extension casing 12, and a gear casing 13.

A motor 14 is contained inside the top cover 11. The motor 14 is positioned above water. The motor 14 is an electric motor rotationally driven by power supply from an accumulator such as a battery.

The motor 14 includes an output shaft 15 integrally driven by rotation of its rotor. The output shaft 15 extends in a substantially perpendicular direction, extending downward under the motor 14.

The lower surface of the top cover 11 is sealed against the extension casing 12, and the lower surface of the top cover 11 is formed as an oil pan 22.

An oil pump 16 driven by rotation of the output shaft 15 is provided on the output shaft 15 near the lower portion of the motor 14.

Planetary gears 17 for deceleration are provided on the output shaft 15 under the oil pump 16.

To the planetary gears 17, a vertical shaft 18 extending downward and passing through the inside of the extension casing 12 is connected.

The lower end part of the vertical shaft 18 is connected to a propeller shaft 20 via transmission gears 19 contained inside the gear casing 13.

A propeller 21 is attached to the tip part of the propeller shaft 20.

As shown in FIG. 1 and FIG. 2 , an oil intake tube (not shown) extending in the up-down direction is provided inside the top cover 11. The lower end part of the oil intake tube is arranged near the bottom part of the oil pan 22 so as to be immersed in cooling oil stored in the oil pan 22. An oil intake port is provided on the oil intake tube via a not-shown strainer.

As shown in FIG. 3 , oil ejection tubes 33 extending in the up-down direction are provided on the outer peripheral part of the motor 14. A plurality of (in the present embodiment, six) oil ejection tubes 33 are provided in the circumferential direction of the motor 14.

To the upper end part of an oil feeding tube 30, branch tubes 34 are connected that feed the cooling oil to the upper end parts of the oil ejection tubes 33.

Oil ejection ports 35 that eject the cooling oil are provided at positions, on the oil ejection tubes 33, corresponding to the outer circumferential surface of the motor 14. A plurality of oil ejection ports 35 are provided on each oil ejection tube 33 along the up-down direction.

Under the motor, the oil feeding tube 30 is provided so as to extend in the up-down direction, the oil feeding tube 30 collecting and feeding the cooling oil after cooling to a heat exchanging part 40 mentioned later. To a lower end part 32 of the oil feeding tube 30, a joining pipe 31 joined to a cooling oil feeding pipe 43 is connected.

The cooling oil after cooling the motor 14 is collected in a lower part of the motor 14 and fed to the heat exchanging part 40 via the oil feeding tube 30, the joining pipe 31, and the cooling oil feeding pipe 43. Meanwhile, the cooling oil having been cooled in the heat exchanging part 40 is fed to the branch tubes 34 above via a cooling oil return pipe 47 and cools the motor 14, and after that, is returned to the oil pan 22.

As shown in FIG. 4 and FIG. 5 , the heat exchanging part 40 is provided inside a front portion of the gear casing 13. The heat exchanging part 40 corresponds to the place, for example, for an engine-driven outboard engine, to contain a switching mechanism that switches the propeller 21 between the state of rotation in the advancing direction and the state of rotation in the reversing direction since the rotational direction of the output shaft of the engine is fixed.

Therefore, room for the heat exchanging part 40 can be obtained without processing when the gear casing 13 for such an engine-driven outboard engine is shared.

A substantially cylindrical oil channel member 41 is contained in the heat exchanging part 40. The oil channel member 41 is formed so as to have a predetermined gap with respect to an inner surface of the heat exchanging part 40. Moreover, a part of the oil channel member 41 is in contact with a bottom surface (inner surface) of the heat exchanging part 40.

An inflow-side oil channel 42 extending in the up-down direction is formed inside the oil channel member 41. To the upper end part of the inflow-side oil channel 42, an oil feeding port 44 connected to the cooling oil feeding pipe 43 is connected.

At the lower end part of the inflow-side oil channel 42, a lower communication channel 45 communicating with the outer circumferential surface of the oil channel member 41 is formed.

An outflow-side oil channel 46 is set between the inner surface of the heat exchanging part 40 and the outer surface of the oil channel member 41.

At the upper end part of the outflow-side oil channel 46, an oil return port 48 connected to the cooling oil return pipe 47 is formed.

Upper communication channels 49 that allow communication from the outer circumferential surface to the oil return port 48 are formed in the oil channel member 41.

This allows a configuration that the cooling oil fed from the cooling oil feeding pipe 43 flows sequentially through the oil feeding port 44, the inflow-side oil channel 42, the lower communication channel 45, the outflow-side oil channel 46, the upper communication channels 49, and the oil return port 48, is fed to the branch tubes 34 above from the cooling oil return pipe 47, and after cooling the motor 14, is returned to the oil pan 22.

Further, the heat exchanging part 40 is formed on a front side of the gear casing 13, and while a vessel is travelling using the outboard engine, running water is to touch the portion of the heat exchanging part 40 of the gear casing 13. Therefore, the cooling oil can be efficiently cooled through heat exchange between the running water and the cooling oil flowing in the outflow-side oil channel 46 of the heat exchanging part 40.

Moreover, a part of the oil channel member 41 is in contact with a bottom surface (inner surface) of the heat exchanging part 40, this allows the oil channel member 41 to be more cooled through thermal conduction with the wall surface of the heat exchanging part 40 while the gear casing 13 is being cooled by the running water, and therefore, the efficiency of cooling the cooling oil can be more enhanced.

Next, operation of the present embodiment is described.

In the present embodiment, by driving the motor 14, a driving force of the motor 14 is transmitted to the propeller shaft 20 via a rotary shaft, the planetary gears 17 for deceleration, and the vertical shaft 18, and thereby, rotates the propeller 21 to advance or reverse the vessel.

Driving the motor 14 also leads to driving the oil pump 16 simultaneously.

When the oil pump 16 is driven, the cooling oil stored in the oil pan 22 is sucked from the oil intake port via the oil intake tube and the strainer and is fed to the heat exchanging part 40.

The cooling oil fed to the heat exchanging part 40 is caused to flow through the oil feeding port 44, the inflow-side oil channel 42, the lower communication channel 45, and the outflow-side oil channel 46.

Further, since running water touches the heat exchanging part 40 of the gear casing 13 thereby to cool the heat exchanging part 40, the cooling oil is efficiently cooled down to the temperature of the running water while flowing in the inflow-side oil channel 42, the lower communication channel 45, and the outflow-side oil channel 46.

After that, the cooling oil having been cooled is fed to the oil ejection tubes 33 via the branch tubes 34 from the cooling oil return pipe 47 sequentially via the upper communication channels 49 and the oil return port 48, and is ejected to the outer circumferential surface of the motor 14 from the oil ejection ports 35.

Thereby, the outer periphery of the motor 14 is cooled with the cooling oil.

As mentioned above, there are included in the present embodiment: the motor 14 contained in the top cover 11; the vertical shaft 18 that is rotationally driven by the motor 14, the vertical shaft 18 being contained in the extension casing; and the propeller 21 that is rotationally driven by the vertical shaft 18, the propeller 21 being provided at the gear casing 13, wherein the heat exchanging part 40 is provided inside a front portion of the gear casing 13, and inside the heat exchanging part 40, the inflow-side oil channel 42 and the outflow-side oil channel 46 (oil channels) are formed that the cooling oil for cooling the motor 14 flows through.

Accordingly, since the heat exchanging part 40 is formed in a front portion of the gear casing 13, running water is to touch the heat exchanging part 40 while a vessel is travelling using the outboard engine. Therefore, by forming the oil channels in the heat exchanging part 40, the cooling oil flowing in the oil channels can be efficiently cooled.

Moreover, in the present embodiment, the tubular oil channel member 41 is provided in the heat exchanging part 40, in the oil channel member 41, the inflow-side oil channel 42 that allows the cooling oil fed from the motor 14 to flow through, and between an inner surface of the heat exchanging part 40 and an outer surface of the oil channel member 41, the outflow-side oil channel 46 is formed that returns the cooling oil to the motor 14.

Accordingly, since the cooling oil fed from the motor 14 flows through the inflow-side oil channel 42 formed inside the oil channel member 41, and after that, flows through the outflow-side oil channel 46 formed between the inner surface of the heat exchanging part 40 and the outer surface of the oil channel member 41, by the outflow side of the cooling oil being positioned outward of the oil channel member 41, the cooling oil can be efficiently cooled.

Moreover, in the present embodiment, a part of the oil channel member 41 is in contact with an inner surface of the heat exchanging part 40.

Accordingly, a part of the oil channel member 41 is in contact with a bottom surface (inner surface) of the heat exchanging part 40, this allows the oil channel member 41 to be more cooled through thermal conduction with the wall surface of the heat exchanging part 40 while the gear casing 13 is being cooled by running water, and therefore, the efficiency of cooling the cooling oil can be more enhanced.

[Modification]

FIG. 6 is an elevational sectional view showing a modification of the heat exchanging part 40.

A shape of the oil channel member 41 of the heat exchanging part 40 is not limited to a circular cylinder shape but, for example, as shown in FIG. 6 , may be made into a shape to meet the interior shape of the heat exchanging part 40.

By shaping as above, the oil channel member 41 can be installed regardless of the shape of the heat exchanging part 40 to cool the cooling oil.

FIG. 7 is a schematic configuration view showing a modification of the heat exchanging part 40.

As shown in FIG. 7 , in this modification, there are provided in the heat exchanging part 40 a plurality of inflow-side oil pipes 50 constituting an inflow-side oil channel and a plurality of outflow-side oil pipes 51 constituting an outflow-side oil channel.

By configuring as above, the cooling oil flowing in the oil channel can be efficiently cooled with the plurality of inflow-side oil pipes 50 and the plurality of outflow-side oil pipes 51.

Moreover, since the cooling oil is cooled with the inflow-side oil pipes 50 and the outflow-side oil pipes 51, the oil channel member 41 is not needed.

Furthermore, by bringing parts of the inflow-side oil pipes 50 and the outflow-side oil pipes 51 into contact with an inner surface of the heat exchanging part 40, a contact surface area of the heat exchanging part 40 with the cooling oil on the inflow-side and the cooling oil on the outflow-side can be increased, and the effect of cooling the cooling oil can be enhanced.

FIG. 8 is a transverse sectional view showing a modification of the heat exchanging part 40.

As shown in FIG. 8 , on a lateral surface of the gear casing 13, recess parts 52 may be formed so as to go along the shape of the heat exchanging part 40.

By forming the recess parts 52 as above, a contact surface area of the outer surface of the heat exchanging part 40 with running water can be increased, and the heat exchanging part 40 can be more cooled. Accordingly, the efficiency of cooling the cooling oil can be enhanced.

FIG. 9 is a transverse sectional view showing a modification of the heat exchanging part 40.

As shown in FIG. 9 , the heat exchanging part 40 of the gear casing 13 may be formed into a shape to be separated from the place where the vertical shaft 18 is inserted.

By forming the gear casing 13 as above, a contact surface area of the outer surface of the heat exchanging part 40 with running water can be increased, and the heat exchanging part 40 can be more cooled. Accordingly, the efficiency of cooling the cooling oil can be enhanced.

While the present invention has been described with the aforementioned embodiment, the present invention is not limited to the aforementioned embodiment but various alterations, substitutions, additions, and omissions may occur as needed.

[Configurations Supported by the Aforementioned Embodiment]

The aforementioned embodiment supports the following configurations

(Configuration 1)

An outboard engine comprising: a motor contained in a top cover; a vertical shaft that is rotationally driven by the motor, the vertical shaft being contained in an extension casing; and a propeller that is rotationally driven by the vertical shaft, the propeller being provided at a gear casing, wherein a heat exchanging part is provided inside a front portion of the gear casing, and inside the heat exchanging part, an oil channel is formed that cooling oil for cooling the motor flows through.

According to this configuration, since the heat exchanging part is formed in a front portion of the gear casing, running water is to touch the heat exchanging part while a vessel is travelling using the outboard engine. Therefore, by forming the oil channel in the heat exchanging part, the cooling oil flowing in the oil channel can be efficiently cooled.

(Configuration 2)

The outboard engine according to Configuration 1, wherein a tubular oil channel member is provided in the heat exchanging part, in the oil channel member, an inflow-side oil channel is formed that allows the cooling oil fed from the motor to flow through, and between an inner surface of the heat exchanging part and an outer surface of the oil channel member, an outflow-side oil channel is formed that returns the cooling oil to the motor.

According to this configuration, since the cooling oil fed from the motor flows through the inflow-side oil channel formed inside the oil channel member, and after that, flows through the outflow-side oil channel formed between the inner surface of the heat exchanging part and the outer surface of the oil channel member, by the outflow side of the cooling oil being positioned outward of the oil channel member, the cooling oil can be efficiently cooled.

(Configuration 3)

The outboard engine according to Configuration 1 or Configuration 2, wherein a part of the oil channel member is in contact with an inner surface of the heat exchanging part.

According to this configuration, a part of the oil channel member is in contact with a bottom surface (inner surface) of the heat exchanging part, this allows the oil channel member to be more cooled through thermal conduction with the wall surface of the heat exchanging part while the gear casing is being cooled by running water, and therefore, the efficiency of cooling the cooling oil can be more enhanced.

(Configuration 4)

The outboard engine according to any one of Configuration 1 to Configuration 3, wherein the heat exchanging part is formed into a shape that meets an outer shape of the oil channel member.

According to this configuration, the oil channel member can be installed regardless of the shape of the heat exchanging part to cool the cooling oil.

(Configuration 5)

The outboard engine according to Configuration 1, wherein there are formed inside the heat exchanging part a plurality of inflow-side oil channels that allow the cooling oil fed from the motor to flow through and a plurality of outflow-side oil channels that return the cooling oil to the motor.

According to this configuration, by forming the plurality of inflow-side oil channels and the plurality of outflow-side oil channels, the cooling oil flowing in the oil channel can be efficiently cooled.

REFERENCE SIGNS LIST

-   -   10 Outboard engine     -   11 Top cover     -   12 Extension casing     -   13 Gear casing     -   14 Motor     -   15 Output shaft     -   16 Oil pump     -   18 Vertical shaft     -   19 Transmission gear     -   21 Propeller     -   22 Oil pan     -   30 Oil feeding tube     -   33 Oil ejection tube     -   34 Branch tube     -   35 Oil ejection port     -   40 Heat exchanging part     -   41 Oil channel member     -   42 Inflow-side oil channel     -   43 Cooling oil feeding pipe     -   44 Oil feeding port     -   45 Lower communication channel     -   46 Outflow-side oil channel     -   47 Cooling oil return pipe     -   48 Oil return port     -   49 Upper communication channel     -   50 Inflow-side oil pipe     -   51 Outflow-side oil pipe     -   52 Recess part 

What is claimed is:
 1. An outboard engine comprising: a motor contained in a top cover; a vertical shaft that is rotationally driven by the motor, the vertical shaft being contained in an extension casing; and a propeller that is rotationally driven by the vertical shaft, the propeller being provided at a gear casing, wherein a heat exchanging part is provided inside a front portion of the gear casing, and inside the heat exchanging part, an oil channel is formed that cooling oil for cooling the motor flows through.
 2. The outboard engine according to claim 1, wherein a tubular oil channel member is provided in the heat exchanging part, in the oil channel member, an inflow-side oil channel is formed that allows the cooling oil fed from the motor to flow through, and between an inner surface of the heat exchanging part and an outer surface of the oil channel member, an outflow-side oil channel is formed that returns the cooling oil to the motor.
 3. The outboard engine according to claim 2, wherein a part of the oil channel member is in contact with an inner surface of the heat exchanging part.
 4. The outboard engine according to claim 2, wherein the heat exchanging part is formed into a shape that meets an outer shape of the oil channel member.
 5. The outboard engine according to claim 1, wherein there are formed inside the heat exchanging part a plurality of inflow-side oil channels that allow the cooling oil fed from the motor to flow through and a plurality of outflow-side oil channels that return the cooling oil to the motor. 